Preconditioned air unit with self-contained cooling modules

Abstract

A preconditioned air unit for supplying preconditioned air to an aircraft parked on the ground, the preconditioned air unit comprising a main unit with a housing accommodating a flow duct with an air inlet for ambient air and an air outlet for connection to the parked aircraft, a blower connected with the flow duct for generation of an air flow from the air inlet toward the air outlet, and a plurality of compartments, each of which is configured for accommodation of a self-contained cooling module comprising at least one refrigeration system, each of which includes at least one compressor, at least one condenser, at least one expansion valve, and at least one evaporator connected in a flow circuit containing a refrigerant, and wherein each compartment is further configured so that the at least one evaporator interacts with the air flow in the flow duct when the self-contained cooling module is installed in the compartment, and wherein at least one self-contained cooling module is installed in the plurality of compartments.

The invention claimed is: 
     
       1. A preconditioned air unit for supplying preconditioned air to an aircraft parked on the ground, the preconditioned air unit comprising a main unit with a housing accommodating
 a flow duct including a partition with an air inlet for ambient air and an air outlet for connection to the parked aircraft, 
 a blower connected with the flow duct for generation of an air flow from the air inlet toward the air outlet, and 
 a plurality of compartments, each of which is configured for accommodation of a self-contained cooling module comprising
 at least one refrigeration system, each of which includes at least one compressor, at least one condenser, at least one expansion valve, and at least one evaporator connected in a flow circuit containing a refrigerant, and wherein 
 each compartment is further configured so that the at least one evaporator interacts with the air flow in the flow duct when the self-contained cooling module is installed in the compartment, and wherein 
 
 a plurality of self-contained cooling modules are installed in the plurality of compartments. 
 
     
     
       2. The preconditioned air unit according to  claim 1 , wherein
 at least one of the compartments is configured for removable installment of one of the self-contained cooling modules therein. 
 
     
     
       3. The preconditioned air unit according to  claim 1 , wherein
 the self-contained cooling module has physical dimensions suitable for movement by a fork lift truck. 
 
     
     
       4. The preconditioned air unit according to  claim 1 , further comprising at least one variable frequency driver for power supply of at least one of the at least one compressor of the at least one self-contained cooling module. 
     
     
       5. The preconditioned air unit according to  claim 1 , wherein at least one of the self-contained cooling modules includes at least one variable frequency driver connected for power supply of at least one of the at least one compressor. 
     
     
       6. The preconditioned air unit according to  claim 1 , further comprising at least one condenser fan for generation of an airflow interacting with at least one of the at least one condenser of the at least one self-contained cooling module. 
     
     
       7. The preconditioned air unit according to  claim 1 , wherein at least one of the self-contained cooling modules includes at least one condenser fan for generation of an airflow interacting with at least one of the at least one condenser. 
     
     
       8. The preconditioned air unit according to  claim 6 , further comprising at least one variable frequency driver connected for power supply of at least one of the at least one condenser fan. 
     
     
       9. The preconditioned air unit according to  claim 7 , wherein the at least one self-contained cooling module further comprises at least one variable frequency driver connected for power supply of at least one of the at least one condenser fan. 
     
     
       10. The preconditioned air unit according to  claim 1 , wherein the housing further accommodates a variable frequency driver connected for electrical power supply of the blower. 
     
     
       11. The preconditioned air unit according to  claim 4 , wherein at least one of the at least one variable frequency driver has a controller that is configured for variation of the output frequency of the at least one variable frequency driver. 
     
     
       12. The preconditioned air unit according to  claim 11 , wherein the controller is configured for variation of the output frequency of the at least one variable frequency driver above the frequency of the mains supply of the preconditioned air unit. 
     
     
       13. The preconditioned air unit according to  claim 11 , wherein the controller of the at least one variable frequency driver is further configured for adjustment of the output frequency in response to a sensor output connected to the controller. 
     
     
       14. The preconditioned air unit according to  claim 4 , wherein at least one variable frequency driver keeps the ratio between the output voltage and the frequency substantially constant to maintain a high motor torque throughout the entire output frequency range. 
     
     
       15. The preconditioned air unit according to  claim 1 , wherein the housing further accommodates a central controller that is configured for controlling the operation of the preconditioned air unit. 
     
     
       16. The preconditioned air unit according to  claim 15 , wherein the central controller is connected to at least one controller of the variable frequency drivers. 
     
     
       17. The preconditioned air unit according to  claim 15 , wherein the central controller has a power sharing control input for control of preconditioned air unit power consumption. 
     
     
       18. The preconditioned air unit according to  claim 15 , wherein the central controller automatically adjusts the cooling performed by the preconditioned air unit to at least one of: The selected type of aircraft, the ambient temperature, the humidity, the cabin temperature, and the outgoing airflow from the preconditioned air unit. 
     
     
       19. The preconditioned air unit according to  claim 16 , wherein each of the refrigeration systems is configured for failure detection so that, in the event that one of the refrigeration systems fails, the failing cooling refrigeration system transmits a failure signal to the central controller. 
     
     
       20. The preconditioned air unit according to  claim 19 , wherein the central controller is further configured to automatically adjust the required amount of cooling among the remaining properly operating refrigeration systems of the preconditioned air unit in response to the failure signal. 
     
     
       21. The preconditioned air unit according to  claim 1 , wherein the housing further accommodates a rectifier connected to a mains supply input of the preconditioned air unit for generation of a power DC voltage supply. 
     
     
       22. The preconditioned air unit according to  claim 21 , wherein the rectifier is selected from the group consisting of a 12-pulse rectifier, an 18-pulse rectifier, and a 24-pulse rectifier. 
     
     
       23. The preconditioned air unit according to  claim 1 , further comprising at least one of: A user interface panel with input keys and a display, a remote control, a computer interface, a network interface, and a loudspeaker. 
     
     
       24. The preconditioned air unit according to  claim 1 , further comprising a heater in the flow duct. 
     
     
       25. A device, comprising:
 a preconditioned air unit for supplying preconditioned air to an aircraft parked on the ground, the preconditioned air unit including: 
 a main unit with a housing accommodating a flow duct including a partition with an air inlet for ambient air and an air outlet for connection to the parked aircraft, 
 a blower connected with the flow duct for generation of an air flow from the air inlet toward the air outlet, and 
 a plurality of compartments, each of which is configured for accommodation of a self-contained cooling module comprising:
 at least one refrigeration system, each of which includes at least one compressor, at least one condenser, at least one expansion valve, and at least one evaporator connected in a flow circuit containing a refrigerant, wherein respective evaporators are located in the flow duct, and wherein at least respective condensers are located outside of the flow duct, wherein 
 
 each compartment is further configured so that the at least one evaporator interacts with the air flow in the flow duct when the self-contained cooling module is installed in the compartment, and wherein 
 a plurality of self-contained cooling modules are installed in the plurality of compartments. 
 
     
     
       26. The device of  claim 25 , wherein:
 respective condensers and respective compressors are located outside the flow duct. 
 
     
     
       27. The device of  claim 25 , wherein:
 the device is configured to draw in ambient air for heat removal of heat from the condensers, wherein the ambient air drawn in for heat removal is channeled through the device and exhausted to an ambient environment of the device. 
 
     
     
       28. The device of  claim 25 , wherein:
 the inlet and outlet are located proximate one another. 
 
     
     
       29. The device of  claim 25 , further comprising:
 a heater located in the flow duct. 
 
     
     
       30. The preconditioned air unit according to  claim 1 , wherein
 the preconditioned air unit is configured such that at least one of the self-contained cooling modules is located upstream from the blower and at least one of the self-contained cooling modules is located downstream from the blower. 
 
     
     
       31. The preconditioned air unit according to  claim 1 , wherein:
 the self-contained cooling modules include respective support structures separate from the housing, the respective support structures supporting the respective at least one compressor, the at least one condenser, the at least one expansion valve and the at least one evaporator of each self-contained cooling module such that removal of the support structures from the housing removes the respective at least one compressor, the at least one condenser, the at least one expansion valve and the at least one evaporator of each self-contained cooling module. 
 
     
     
       32. The preconditioned air unit according to  claim 1 , wherein:
 the preconditioned air unit is configured to cool air in multiple steps via the plurality of self-contained cooling modules thereby protecting a downstream evaporator from freezing over. 
 
     
     
       33. The preconditioned air unit according to  claim 6 , wherein the preconditioned air unit includes a component made of metal, and wherein airflow generated by the at least one condenser fan is separate from the airflow generated by the blower and travels a separate path from the airflow generated by the blower. 
     
     
       34. A preconditioned air unit for supplying preconditioned air to an aircraft parked on the ground, the preconditioned air unit comprising a main unit with a housing accommodating
 a flow duct including a partition with an air inlet for ambient air and an air outlet for connection to the parked aircraft, both the air inlet and the air outlet being located at a same side of the housing, 
 a blower including a blower fan, the blower fan located within the flow duct and configured to generate an air flow from the air inlet toward the air outlet, and 
 a plurality of compartments, each of which is configured for accommodation of a self-contained cooling module comprising
 at least one refrigeration system, each of which includes at least one compressor, at least one condenser, at least one expansion valve, and at least one evaporator connected in a flow circuit containing a refrigerant, and wherein 
 each compartment is further configured so that the at least one evaporator interacts with the air flow in the flow duct when the self-contained cooling module is installed in the compartment, and wherein 
 
 a plurality of self-contained cooling modules are installed in the plurality of compartments. 
 
     
     
       35. The preconditioned air unit according to  claim 6 , wherein the preconditioned air unit includes a pan. 
     
     
       36. A preconditioned air unit for supplying preconditioned air to an aircraft parked on the ground, the preconditioned air unit comprising a main unit with a housing accommodating
 a flow duct including a partition with an air inlet for ambient air and an air outlet for connection to the parked aircraft, 
 a blower connected with the flow duct for generation of an air flow from the air inlet toward the air outlet, and 
 an enclosure with a plurality of corners, each of which is configured for accommodation of a functioning cooling circuit comprising
 at least one refrigeration system, each of which includes at least one compressor, at least one condenser, at least one expansion valve, and at least one evaporator connected in a flow circuit containing a refrigerant, and wherein 
 each compartment is further configured so that the at least one evaporator interacts with the air flow in the flow duct when the self-contained cooling circuit is installed in the compartment, and wherein 
 
 parts for a plurality of functioning cooling circuits are installed in the plurality of corners. 
 
     
     
       37. The device of  claim 25 , wherein:
 the device is configured such that the respective self-contained cooling modules are movable into and out of the housing using a forklift. 
 
     
     
       38. The device of  claim 25 , wherein:
 the device is configured such that the respective self-contained cooling modules are movable into and out of the housing by moving the respective modules in a transverse direction to a direction of the flow duct. 
 
     
     
       39. The device of  claim 25 , wherein:
 the device is configured such that the flow of air from the inlet to the outlet travels in a “U” direction. 
 
     
     
       40. The device of  claim 25 , wherein:
 the flow duct fluidically links the air inlet to the air outlet.